1. Technological Field
This present technology pertains generally to image coding mode decisions, and more particularly to generating joint mode decisions when performing embedded block coding.
2. Background Discussion
Increasingly, image coding systems are moving towards forms of scalable coding, such as resolution-scalable and distortion-scalable. One such system is defined in the JPEG 2000 standard, which uses discrete wavelet transforms (DWT) instead of a discrete cosine transform (DCT). JPEG 2000 has a resolution scalable bit stream.
However, many dependencies are introduced with standard bit-plane coding which has excessive interaction between coding and ordering, that complicate scalability. One mechanism utilized to overcome these dependency issues is to partition the samples into small blocks which are coded independently, this is what is performed by embedded block coding (EBC). There are numerous forms of EBC which exist, such as embedded block coding with optima truncation (EBCOT).
In EBC, each block generates independent bit-streams which are packed into quality layers. Within each quality layer the independent bit streams are subdivided into a large number of “chunks”. While preserving the ordering of chunks of a block, the compression system can interleave chunks from the block in a desired manner, each chunk providing incremental contributions to the given quality layer.
However, the independently coded blocks each have a limited bit budget whose use is not always beneficially maximized.
Accordingly, the technology presented is configured for optimizing the use of the bit budget in systems utilizing forms of embedded block coding.